Hey, Jenny, I've got your number! And I'm going to punch it into one of these nice matrix keypads. We have a bunch of different options in 3x4- and 4x4-grid styles. These are an easy way to add some input options to your project!
The keys are connected into a matrix, so for the 3x4 matrix keypads, you only need 7 microcontroller pins (3-columns and 4-rows) to scan through the pad. On the 4x4 matrix keypads, you only need 8 microcontroller pins (4-columns and 4-rows) to scan through the pad.
We have libraries in Arduino and CircuitPython to make getting started super simple and fast.
So wire it up to your project, and punch in your secret key to open all the possibilities!